Duong Thi Thanh Tu

Bio: Duong Thi Thanh Tu is an academic researcher from Posts and Telecommunications Institute of Technology. The author has contributed to research in topics: Antenna (radio) & Multi-band device. The author has an hindex of 3, co-authored 10 publications receiving 39 citations.

28/38 GHz dual-band MIMO antenna with low mutual coupling using novel round patch EBG cell for 5G applications

Abstract: In this paper, a 4×4 dual-band Multiple Input Multiple Output (MIMO) antenna which operates at 28 and 38 GHz bands for future fifth-generation (5G) wireless technology is proposed. Based on RT5880 with height of 0.79mm, the total size of MIMO antenna is 19.25 × 26 × 0.79 mm3. With structure of 1×2 phased array single antenna, the MIMO antenna gets wide-bands of 14.3% and 5.26% at 28 GHz and 38 GHz, respectively. Besides, the MIMO antenna achieves low mutual coupling for all operating bands with close distance of 0.7mm thanks to using novel round patch Electromagnetic Band Gap (EBG) cell. The design of dual-band MIMO antenna is optimized and validated by simulation using CST-MW Studio as well as by measurement.

Improving Characteristics of 28/38GHz MIMO Antenna for 5G Applications by Using Double-Side EBG Structure

Abstract: — Multiple Input Multiple Output (MIMO) antenna is expected to form a major technique of 5G communication to get a high channel capacity. However the antenna performance is degraded significantly because of mutual coupling between close elements in portable equipments. In this paper, a novel EBG structure for 28/38GHz dual-band MIMO antenna with its equivalent is proposed. Having round shape and double side design, the proposed double-side EBG (DS-EBG) structure is able to improve significantly both mutual coupling and gain without any decoupling structure between antenna elements. Thus the MIMO antenna gets compact size of 15.3x8.5x0.79mm with no distance between antenna elements from edge to edge. The antenna radiation efficiency is also refined at both bands. This improvement has not attained from any previous EBG structure studies. At 28GHz, the radiation efficiency is increased from 83.2% to 87.6% while it is raised from 83.1% to 91.1% at 38GHz. Besides, the antenna achieves wide bandwidth of 7.1% and 13.16% at 28GHz and 38GHz, respectively that is suitable for 5G terminals. All dimensions of EBG cell as well as antenna are optimized by using Computer Simulation Technology (CST) software.

Compact MIMO antenna with low mutual coupling using defected ground structure

Abstract: Defected Ground Structure (DGS) is a newly introduced revolutionary technique in the field of microstrip antenna to enhance the performance of antenna parameters as bandwidth. In this paper, a design of compact MIMO antenna using DGS is proposed. The antenna operates at 3.5 GHz for WiMax/LTE tablet applications. Compare to theoretical microstrip antenna design, the suggested MIMO antenna using a simple DGS shape has achieved not only an enlarged bandwidth but also more compact size. In addition, the mutual coupling between two antenna elements with close distance is low (less than −20dB) thanks to proper position in antenna ground as well as the fed method using.

Design and Implementation of Dual-Band MIMO Antenna with Low Mutual Coupling Using EBG for Handheld Applications

Abstract: A dual-band Multiple Input Multiple Output (MIMO) antenna system with enhanced isolation for LTE and WLAN applications is proposed. Using a double-rectangular Defected Ground Structure (DGS), the MIMO antenna gets two resonant frequencies of 2.6 GHz and 5.7 GHz with bandwidth of 5.7% and 4.3% respectively. To reduce much more mutual coupling between dual-band MIMO antenna ports, a novel double-side Electromagnetic Band Gap (EBG) structure with equivalent circuit model is proposed. Size of t gain of the antenna is getting better, especially at the low band. he EBG unit cell is 8.6x8.6 mm2 that is built on FR4 substrate with height of 1.6 mm, so it is achieved more compact size than conventional EBG structures. With 1x7 EBG structures, the mutual coupling gets -40dB in the low frequency band and -30 dB in the high one with narrow distance of 0.11 from feeding point to feeding point. Furthermore, radiation efficiency as well as gain of the antenna is getting better, especially at the low band.

Compact, Wide-Band and Low Mutual Coupling MIMO Metamaterial Antenna using CPW Feeding for LTE/Wimax Applications

Abstract: In this paper, a metamaterial antenna is designed by using coplanar waveguide (CPW) feeding to obtain wideband and compact size. The Multiple-Input Multiple-Output (MIMO) antenna is constructed by placing side-by-side two single metamaterial antennas which are based on the modified composite right/left handed (CRLH) model. The proposed antenna covers 22% of the experimental bandwidth for both cases of single and MIMO antennas. Implemented in FR4 substrate with the height of 1.6 mm, the antenna is compact in size with radiating patch dimension of 5.75x14 mm2 at 3.5 GHz resonant frequency that is suitable for Long Term Evolution (LTE)/Wimax applications in handheld devices. Furthermore, the combination of Defected Ground Structure (DGS) and enlarged ground of coplanar structure has solved the challenge of mutual coupling between elements in the MIMO metamaterial antenna using CPW feeding. With the distance of 0.46\lambda_0 between feeding points, the MIMO antenna obtains the high isolation of under −20 dB for a huge bandwidth with a good agreement between simulations and measurements. DOI: 10.32913/rd-ict.vol2.no15.676

Eye tracking algorithms, techniques, tools, and applications with an emphasis on machine learning and Internet of Things technologies

Abstract: Eye tracking is the process of measuring where one is looking (point of gaze) or the motion of an eye relative to the head. Researchers have developed different algorithms and techniques to automatically track the gaze position and direction, which are helpful in different applications. Research on eye tracking is increasing owing to its ability to facilitate many different tasks, particularly for the elderly or users with special needs. This study aims to explore and review eye tracking concepts, methods, and techniques by further elaborating on efficient and effective modern approaches such as machine learning (ML), Internet of Things (IoT), and cloud computing. These approaches have been in use for more than two decades and are heavily used in the development of recent eye tracking applications. The results of this study indicate that ML and IoT are important aspects in evolving eye tracking applications owing to their ability to learn from existing data, make better decisions, be flexible, and eliminate the need to manually re-calibrate the tracker during the eye tracking process. In addition, they show that eye tracking techniques have more accurate detection results compared with traditional event-detection methods. In addition, various motives and factors in the use of a specific eye tracking technique or application are explored and recommended. Finally, some future directions related to the use of eye tracking in several developed applications are described.

Printed millimeter-wave MIMO-based slot antenna arrays for 5G networks

Abstract: In this work, a broadband millimeter-wave (mm-wave) multiple-input–multiple-output (MIMO) antenna system for upcoming fifth generation (5G) networks is presented. The MIMO antenna system is two ports and realized using two antenna arrays, aligned in opposite directions. Each array consist of three elements in each, as each element is a simple recognized printed wide-slot antenna proximity excited by microstrip line with a widened tuning stub; manipulated for operating in the Ka-band, which includes the 28 and 38 GHz bands, as potential candidates for 5G communications. An electromagnetic band-gap (EBG) reflector is placed behind the antenna structure toward the feeding network to decrease the backward radiation and improve the front-to-back (F/B) ratio. Results show that the proposed MIMO antenna system with EBG reflector provides wideband impedance bandwidth >27 GHz (from 22.5 to >50 GHz) and good radiation characteristics with a total realized gain up to 11.5 and 10.9 dBi at the two frequencies of interest, respectively. The envelope correlation coefficient (ECC) and diversity gain (DG) were evaluated and showed good MIMO performance. These remarkable features with the benefits of design simplicity and easily expansion to large-scale antenna system make the proposed design suitable for mm-wave communications.

Planar dual-band 27/39 GHz millimeter-wave MIMO antenna for 5G applications

Abstract: This research work presents another design of a multi-input multi-output (MIMO) antenna with dual wide operating bands at the millimeter-wave (MMW) region proposed for 5G applications. The design consists of two monopole elements with full size of 26 × 11 mm2. The two monopoles are designed to provide dual-band operation at the frequencies 27 GHz and 39 GHz. The mutual coupling between the two elements is studied and optimized to maximally reduce the effect of one element on the other. The S-parameters of the proposed MMW MIMO configuration are simulated using two software and measured using VNA. The results are well agreed with considerable shifting between the measured and the simulated, which can be due to the fabrication tolerance and cable losses. The radiation characteristics are investigated in terms of gain and efficiency. The proposed MIMO manifests acceptable gain that reaches 5 dBi and 5.7 dBi in the first and second bands, respectively, while the radiation efficiency reaches 99.5% and 98.6% over the first and the second bands, respectively. The MIMO performance is also studied where a very low envelope correlation of about 10–4 is obtained and a diversity gain of about 10 dB over the two operating bands is also achieved. The comparison between simulation and measurement shows the possible potential of the proposed MIMO antenna that makes it feasible for MMW 5G applications.

An integrated antenna system for 4G and millimeter-wave 5G future handheld devices

Abstract: In this work, an integrated antenna system with Defected Ground Structure (DGS) is presented for Fourth Generation (4G) and millimeter (mm)-wave Fifth Generation (5G) wireless applications and handheld devices. The proposed design with overall dimensions of 110 mm × 75 mm is modeled on 0.508 mm thick Rogers RT/Duroid 5880 substrate. Radiating structure consists of antenna arrays excited by the T-shape 1 × 2 power divider/combiner. Dual bands for 4G centered at 3.8 GHz and 5.5 GHz are attained, whereas the 10-dB impedance bandwidth of 24.4 - 29.3 GHz is achieved for the 5G antenna array. In addition, a peak gain of 5.41 dBi is demonstrated across the operating bandwidth of the 4G antenna array. Similarly, for the 5G mm-wave configuration the attained peak gain is 10.29 dBi. Moreover, significant isolation is obtained between the two antenna modules ensuring efficient dual-frequency band operation using a single integrated solution. To endorse the concept, antenna prototype is fabricated and far-field measurements are procured. Simulated and measured results exhibit coherence. Also the proposed design is investigated for the beam steering capability of the mm-wave 5G antenna array using CST®MWS®. The demonstrated structure offers various advantages including compactness, wide bandwidth, high gain, and planar configuration. Hence, the attained radiation characteristics prove the suitability of the proposed design for the current and future wireless handheld devices.